Attachment of Gold Nanoparticles to Carbon Nanotubes

Carbon nanotubes were initially chemically modified with an H2SO4-HNO3 treatment, and subsequently activated with Pd-Sn catalytic nuclei via a one-step activation approach. These activated nanotubes were used as precursors for obtaining gold nanoparticles-attached nanotubes via simple electroless plating. This approach provides an efficient method for attachment of metal nanostructures to carbon nanotubes. Such novel hybrid nanostructures are attractive for many applications.     

Platinum‐Decorated Au Porous Nanotubes as Highly Efficient Catalysts for Formic Acid Electro‐Oxidation

Au porous nanotubes (PNTs) were synthesized by a templating technique that involves the chemical synthesis of Ag nanowire precursors, electroless surface modification with Au, and selective etching. A subsequent galvanic replacement reaction between [PtCl₆]^2? and residual Ag generates Pt‐decorated Au porous nanotubes (Pt/Au PNTs), which represents a new type of self‐sustained high surface area electrocatalysts with ultra‐low Pt loading. Structural characterizations with scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X‐ray powder diffraction (XRD) reveal a novel nanoarchitecture with multimodal open porosity and excellent structural continuity and integrity. Cyclic voltammetry (CV) demonstrates that these Pt/Au PNTs possess very high electrocatalytic activity toward formic acid oxidation with enhanced tolerance to CO poisoning.     

大分子自组装特性计算机模拟的研究

包括表面活性剂在内的大分子在溶液中可以形成聚集体的特性,使其在工业和生活领域得到广泛的应用.研究其自组装特性对生命体内两亲大分子的聚集行为以及生物矿化和仿生合成的研究均具有重要意义.本文分别从分子热力学和分子动力学的角度,对以表面活性剂为主的大分子自组装特性计算机模拟的研究进展进行了综述,分析并展望了对大分子溶液体系理论模拟研究的发展前景。     

自组装化学镀银

用三甲氧基巯基丙基硅烷作偶联剂,通过溶剂抽提法获得单分层自组装巯基化 的玻璃。XPS和AES检测了从多层沉积到单分子层形成的过程。将所得的玻璃用于化 学镀银,XPS分析表明,溶液中新生的银通过S-Ag键的形成结合在自组装膜上,银 进一步沉积生成光亮的银镜。对沉积在巯基单分子层自组装后的玻璃上的银层进行 SEM和X射线衍射分析,结果表明用这种方法得到的镀层牢固度优于常规化学镀银所 得银层,晶体结构与常规化学镀银所得层以及金属银的晶体结构一致。     

玻璃上基于自组装和喷墨打印的选位金属沉积

采用氨基硅烷自组装分子对玻璃表面进行修饰; 借助喷墨打印技术, 按照设计好的线路图形把引发化学镀的催化剂“墨水”喷射在上述修饰表面上. 由于自组装分子具有朝向面外的氨基末端能吸附作为催化剂的溶胶或离子, 因而可以起到“有机浆糊”的作用, 使图形化的催化剂层固定在表面上以充当模板, 由于化学镀只在催化剂模板上发生, 从而可获得与设计一致的, 且与基底牢固结合的金属沉积图形. 将该方法拓展应用到玻璃基底上, 着重优化自组装条件, 提高了结合力, 首次实现了玻璃表面上包括金、铜以及镍硼合金在内的多种金属直接成型.     

自组装技术在电磁屏蔽织物加工中的应用

尼龙织物经功能性高分子壳聚糖(CS)预处理后,应用分子自组装技术于其表面自组装钯膜(镀镍前活化).该膜钯微粒为纳米级,比表面较大,催化活性较高.将成膜后的织物化学镀镍磷合金,即可得到屏蔽性能优异的电磁屏蔽织物.正交试验及单因素试验得出CS预处理的最佳工艺条件.SPM、SEM表征活化前后及施镀前后织物表面的形态变化.根据Schelkunoff理论,计算织物的电磁辐射屏蔽效能,其值高于30 dB,相当于屏蔽掉了96.0%以上的电磁波.     

不同化学镀液中p－Si上激光诱导局部沉积铜

在化学镀铜浴液中,p-Si片在彼长为514.5nm的激光束的照射下,得到了选择性的铜镀层。采用AEs、SEM、RBS和电学技术对比了在3种含不同还原剂的镀液中得到的镀层的形貌、组成、界面扩散及电学性质;探讨了液相激光诱导化学沉积铜的机理。     

不同化学镀液中p—Si上激光诱导局部沉积铜

在化学镀铜溶液中，ｐ－Ｓｉ片在波长为５１４．５ｎｍ的激光束的照射下，得到了选择性的铜镀层。采用ＡＥＳ、ＳＥＭ、ＲＢＳ和电学技术对比了在３种含不同还原剂的镀液中得到的镀层的形貌、组成、界面扩散及电学性质，探讨了液相激光诱导化学沉积铜的机理。     

多肽自组装纳米管的研究进展

综述了通过多肽自组装形成纳米管道的各种方法:线形的D,L-α-多肽可以通过分子内的氢键以及主链的空间排斥作用而组装成纳米管,游离寡肽和环肽则可以通过分子间的氢键组装形成纳米管,而两亲多肽则通过疏水相互作用组装成纳米管。     

Shaping Polymer Particles by Carbon Nanotubes

We report the formation of poly(propylene) spherical and ellipsoidal particles templated by carbon nanotubes via solution crystallization. With an increase in nanotube loading, the particle shape changes from sphere to ellipsoid. In the intermediate concentration range, both spherical and ellipsoidal shapes coexist. The particle size decreases with an increase in nanotube loading.

     

磁性金属纳米管的制备、形成机理及潜在应用

磁性金属纳米管因其独特的中空结构和优异的催化、磁性及易修饰等性能,逐步发展成为一类重要的功能纳米材料,受到国内外研究人员的广泛关注。本文综述了近年来模板法制备磁性金属纳米管的主要技术,如电沉积、化学沉积、湿模板、原子沉积及水热合成等,重点阐述了硬模板法制备磁性金属纳米管的特殊策略,并针对不同制备策略下的磁性金属纳米管形成机理进行了评述。另外,对硬模板法合成磁性金属纳米管建立了一个机理模型,分别从基底性能、成核环境、生长环境三方面对磁性纳米管的形成机理进行了探讨。最后简单介绍了磁性金属纳米管的性能及潜在应用,并展望了该领域的发展趋势。     

Self-assembly of nanotubes and ordered mesostructures using weak interactions

Two simple organic compounds, 5-nitroisophthalic acid (npa) and 4,4′-bipyridine (bpy), were used as building blocks for supramolecular self-assembly by hydrothermal synthesis. SEM, TEM, and XRD were used to analyse the multi-step assembly process in which npa and bpy assembled into nanotubes (or nanobelts) of about 30–100 nm in diameter and several millimetres in length and microtubes (or microbelts). The tubes then further assembled to form complex ordered structures, such as pom-pom-shaped and flower-like mesostructures.     

基于金纳米粒子自组装的分光光度法测定半胱氨酸

在pH 4.56的B ritton-Rob inson(B-R)缓冲溶液中,半胱氨酸的SH和NH3 分别与金纳米粒子表面进行共价结合和静电作用,导致金纳米粒子的长距离自组装,形成网状超分子结构,并使金纳米粒子的最大吸收波长从520 nm红移到660 nm。本实验对半胱氨酸引导的金纳米粒子自组装的作用机制进行了研究,建立了操作简便、高灵敏度测定半胱氨酸的分析方法。其线性范围为0.01~0.20 mg/L;检出限为2.8μg/L(3,σ2.3×10-8mol/L)。在实验条件下,其它常见的氨基酸和谷胱甘肽均不干扰测定。     

Effect of Nonsolvent on the Formation of Polymer Nanomaterials in the Nanopores of Anodic Aluminum Oxide Templates

We study the effect of nonsolvent on the formation of polymer nanomaterials in the nanopores of porous templates. Water (nonsolvent) is added into a poly (methyl methacrylate) (PMMA) solution in dimethylformamide (DMF) confined in the nanopores of an anodic aluminum oxide (AAO) template. Water forms a wetting layer on the pore wall and causes the PMMA solution to be isolated in the center of the nanopore, resulting in the formation of PMMA nanospheres or nanorods after the solvent is evaporated. The formation of the polymer nanomaterials induced by nonsolvent is found to be driven by the Rayleigh‐instability‐type transformation. Without adding the nonsolvent, PMMA chains precipitate on the walls of the nanopores after the solvent is evaporated, and PMMA nanotubes are obtained.     

Solvent‐Annealing‐Induced Nanowetting in Templates: Towards Tailored Polymer Nanostructures

We study the solvent‐annealing‐induced nanowetting in templates using porous anodic aluminum oxide membranes. The morphology of polystyrene and poly(methyl methacrylate) nanostructures can be controlled, depending on whether the swollen polymers are in the partial or complete wetting regimes, which are characterized by the spreading coefficient. When the swollen polymers are in the partial wetting regime, polymers wet the nanopores by capillary action, resulting in the formation of polymer nanorods. When the swollen polymers are in the complete wetting regime, polymers form wetting layers in the nanopores, resulting in the formation of polymer nanotubes. The solubility parameters of polymers and solvents are also used to predict the wetting behavior of swollen polymers in cylindrical geometry.     

Micro—patterning of Copper Based on Photolithographed Self—assembly Monolayers

A new method has been develoed for fabrication of copper micro-pattern by selective chemical copper deposition based on photolithographed (3-mercaptopropyl)-trimethoxysilane (MPTS) self-assembly monolayers (SAMs). As confirmed by scanning electron microscopy (SEM), Cu closely replicated the mask features. The present approach makes this technic to be cheap and may be applicable to assembly of microelectronic circuits.     

化学气相沉积法制备氧化锡自组装纳米结构

采用化学气相沉积法在镀有5-10 nm厚金膜的SiO2衬底上, 通过控制生长条件, 实现了二氧化锡纳米结构的自组装生长, 成功制备出了莲花状和菊花状的二氧化锡自组装纳米结构. 利用扫描电子显微镜、X射线衍射等表征分析手段对样品的表面形貌、结构及成份进行表征和研究. 并在此基础上, 讨论了两种自组装纳米结构的生长机制.